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4 (* ||A|| A project by Andrea Asperti *)
6 (* ||I|| Developers: *)
7 (* ||T|| The HELM team. *)
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15 include "basic_2/computation/fpbc_lift.ma".
16 include "basic_2/computation/fpbg.ma".
18 (* GENERAL "BIG TREE" PARALLEL COMPUTATION FOR CLOSURES *********************)
20 (* Advanced properties ******************************************************)
22 lemma lsstas_fpbg: ∀h,g,G,L,T1,T2,l2. ⦃G, L⦄ ⊢ T1 •*[h, g, l2] T2 → (T1 = T2 → ⊥) →
23 ∀l1. l2 ≤ l1 → ⦃G, L⦄ ⊢ T1 ▪[h, g] l1 → ⦃G, L, T1⦄ >[h, g] ⦃G, L, T2⦄.
24 /4 width=5 by fpbc_fpbg, lsstas_fpbc/ qed.
26 lemma ssta_fpbg: ∀h,g,G,L,T1,T2,l. ⦃G, L⦄ ⊢ T1 ▪[h, g] l+1 →
27 ⦃G, L⦄ ⊢ T1 •[h, g] T2 → ⦃G, L, T1⦄ >[h, g] ⦃G, L, T2⦄.
28 /3 width=2 by fpbc_fpbg, ssta_fpbc/ qed.